Question

Indicate the types of isomerism exhibited by the following complexes and draw the structures for these isomers.

a) Stereoisomerism

b) Geometric isomerism

c) Structural isomerism

d) All of the mentioned

Answer 1

Isomerism in coordination complexes includes geometric and optical isomerism, where complexes can have different spatial orientations of the same ligands, as in cis and trans isomers, or exist as non-superimposable mirror images in the case of chiral molecules.

Step-by-step explanation:

Isomerism in coordination compounds refers to the existence of molecules that have the same chemical formula but different structural arrangements. The key types of isomerism for coordination complexes include geometric and optical isomerism. In geometric isomerism, the same atoms are connected through the same types of bonds but with different spatial orientations.

For instance, the square planar complex [Pt(H₂O)₂Br₂] can have cis and trans isomers where the like ligands are adjacent or opposite to each other, respectively. The complex [Co(C₂O₄)₂2Cl₂]³- features a bidentate oxalate ligand '-O₂ CCO₂ˆ' which can lead to several geometric isomers depending on the positions of the chloride ions. In optical isomerism, complexes can exist in forms that are mirror images of each other but are not superimposable, similar to left and right hands. Compounds like [Pt(NH₃)₃3Cl]*, which is square planar, do not exhibit optical isomerism as it lacks chirality.